Explanation:
Since, the atomic number of nitrogen is 7 and its electronic distribution is 2, 5. So, in order to attain stability it needs to gain 3 electrons.
Hence, when it chemically combines another nitrogen atom then as both the atoms are non-metals. So, sharing of electrons will take place.
Also, there is no difference in electronegativity of two nitrogen atoms. Hence, compound formed 
is non-polar covalent in nature.
Answer:
Substitution mutation
Explanation:
A substitution mutation is a type of mutation in which one or more nucleotide base is replaced by another in a sequence. This will result in the replacement of one or more amino acid in the amino acid sequence.
This is the case in this question where the original amino acid sequence was given as: Leucine – Alanine – Glycine – Leucine. After mutation, the following mutated sequence was produced: Leucine – Alanine – Valine – Leucine.
As illustrated above, one would notice that there is replacement of GLYCINE amino acid by VALINE in the mutated sequence, hence, it is an example of SUBSTITUTION MUTATION.
<span>Not to be confused with tetration.
This article is about volumetric titration. For other uses, see Titration (disambiguation).
Acid–base titration is a quantitative analysis of concentration of an unknown acid or base solution.
Titration, also known as titrimetry,[1] is a common laboratory method of quantitative chemical analysis that is used to determine the unknown concentration of an identified analyte. Since volume measurements play a key role in titration, it is also known as volumetric analysis. A reagent, called the titrant or titrator[2] is prepared as a standard solution. A known concentration and volume of titrant reacts with a solution of analyte or titrand[3] to determine concentration. The volume of titrant reacted is called titration volume</span>
Answer:
The answer to your question is Molarity = 0.0708
Explanation:
Data
NaOH 0.05 M Volume 1 = 3.87 ml Volume 2 = 25.11 ml
HCl 15 ml
Process
1.- Find the volume used of NaOH
25.11 - 3.87 = 21.24 ml = 0.02124 l
2.- Write the balanced equation of the reaction
NaOH + HCl ⇒ NaCl + H₂O
3.- Calculate the moles of NaOH in the solution
Molarity = 
moles = Molarity x volume
moles = 0.05 x 0.02124
moles = 0.001062
4.- From the reaction we know that NaOH and HCl react in a proportion 1:1.
1 mol of NaOH ------------- 1 mol of HCl
0.001062 moles of NaOH ------------ x
x = (0.001062 x 1) / 1
x = 0.001062 moles of HCl
5.- Find the molarity of HCl
Molarity = 
Molarity = 0.0708
For this problem we can use half-life formula and radioactive decay formula.
Half-life formula,
t1/2 = ln 2 / λ
where, t1/2 is half-life and λ is radioactive decay constant.
t1/2 = 8.04 days
Hence,
8.04 days = ln 2 / λ
λ = ln 2 / 8.04 days
Radioactive decay law,
Nt = No e∧(-λt)
where, Nt is amount of compound at t time, No is amount of compound at t = 0 time, t is time taken to decay and λ is radioactive decay constant.
Nt = ?
No = 1.53 mg
λ = ln 2 / 8.04 days = 0.693 / 8.04 days
t = 13.0 days
By substituting,
Nt = 1.53 mg e∧((-0.693/8.04 days) x 13.0 days))
Nt = 0.4989 mg = 0.0.499 mg
Hence, mass of remaining sample after 13.0 days = 0.499 mg
The answer is "e"
